The concept of extending the "pot life" of coffee, i.e. that time period during which it retains the flavor and aroma of freshly brewed coffee, by substantially eliminating its exposure to atmosphere while yet retaining the ability to pour coffee in conventional fashion was introduced by applicant's prior U.S. Pat. No. 3,974,758, the disclosure of which is hereby incorporated by reference. In a pour type coffee receptacle, the concept involves sealing the main body of contained coffee with respect to atmosphere. The top of the receptacle is sealed by a movable follower, such as a bellows or bag, and that coffee contained within the lower end of a small pour spout opening into the coffee receptacle adjacent the bottom thereof serves as a liquid seal between atmosphere and the main body of the receptacle contained coffee.
The result is that the only oxidation that can occur takes place at the upper coffee level in the pour spout. By keeping the cross section of the pour spout sufficiently small, that quantity of coffee that is oxidized and subsequently finds its way through the liquid seal to the main reservoir of contained coffee is negligible over the first 4-8 hours depending upon the cross section of the pour spout.
Stated differently, the patented concept involves pouring coffee from the bottom of the pot while keeping the top of the pot sealed with a movable follower maintaining atmospheric pressure on the coffee so that it can be poured without creating a vacuum lock.
Previously, the pour spout for "pouring from the bottom" of the pot has been formed externally of the pot as illustrated in U.S. Pat. No. 3,974,758. This, of course, requires special tooling since conventional coffee pots are not made with small cross section pour spouts opening into the lower portion of the pot.
The purpose of the present invention is to adapt the patented concept for use with conventionally manufactured coffee receptacles and, more particularly, those conventional glass coffee receptacles used with automatic, flow-through coffee makers.